Brahmanism,
the predominant religion in India
during the Buddha's time, divided all humans into four
castes (attu vanna), priests, warriors, traders
and labourers. Social contact between each caste was minimal
and the lower one's position in the system the less opportunities,
the less freedom and the less rights one had. Outside
the caste system were the outcasts (sudra) people
considered so impure that they hardly counted as humans.
The caste system was later absorbed into Hinduism,
given religious sanction and legitimacy and has continued
to function right up till the present. The Buddha, himself
born into the warrior caste, was a severe critic of the
caste system. He ridiculed the priests claims to be superior,
he criticised the theological basis of the system and
he welcomed into the Sangha people of all castes, including outcasts. His
most famous saying on the subject is : " Birth does
not make one a priest or an outcaste. Behaviour makes
one either a priest or an outcaste". Even during
the time when Buddhism was decaying in India and Tantrayana
had adopted many aspects of Hinduism, it continued to
welcome all castes and some of the greatest Tantric adepts
were low castes or outcastes.

Despite
this, various forms of the caste system are practised
in several Buddhist countries, mainly in Sri Lanka,
Tibet, and Japan where butchers, leather and metal workers
and janitors are sometimes regarded as being impure.
However, the system in these countries has never been
either as severe or as rigid as the Hindu system and
fortunately it is now beginning to fade away. The exception
to this is Nepal where Tantric priests form a separate
caste and will neither initiate into their priesthood
or allow into their temples those of other castes.